Apparatus for grinding serrated cutting blades



H. J. CRINER APPARATUS FOR GRINDING SERRATED CUTTING BLADES 2Sheets-Sheet 1 Filed March 4, 1935 INVENTZDR.

Dec. 1, 1936.. H. J. CRINER 2,062,352

APPARATUS FOR GRINDING SERRATED CUTTING BLADES Filed March 4, 1955 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY:

Patented Dec. 1, 1936 UNITED STATES PATENT omen APPARATUS FOR GRINDINGSERRATEID' cur'rme an mus Harry J. Criner, Davenporfllowa, assignor ofone-half to A. G. Bush, Davenport, Iowa Application March 4, 1935,Serial No. 9,260

8 Claims.. (01. 51-72) My invention relates to new and useful improveorfrom serrated strips of metaland for sharpeningold blades. I I attainthese objects by the means illustrated in the accompanying drawings, inwhich,. Figure 1 is an end elevation of my apparatus; Figure 2 isa planview of the same; I

Figure 3 is an enlarged cross-sectional detail of a part of the tiltingtable, blade support and grinding wheel on the line 3-3 of Figure 2;

' Figure 4 is an enlarged detail showing one of the guidingkeys andgrooves engaging same in section on the line 4-4 of Figure 1;

Figure 5 is an enlarged detail of a blade mount-v ed in the bladesupport and showing a portion of the grinding wheel in section;

5 Figure 6 is a plan view of an'alternate form of my invention employinga plurality of grinding preferably made of a heavy flat casting adaptedto seat upon a bench, table-or other support'and may be cast-hollow ifdesired, to reduce weight.

, At the rear of the base a projecting boss, 2,is'

formed integral with the base and the boss and base are bored out toreceive a post or column, 23. I A collar, 24, is slidingly mounted uponthe post,

"23,- with a set screw, 24, by which it may berigidly secured at anydesired height upon the '.column, 23.

A sleeve, 22, is slidingly and revolvably mounted upon the-column,23,above the collar, 24, and is provided with a set screw, 22', by whichit may' be locked in a given position.

This arrangement of a lockable sleeve combined with. a lockable collar,has great advantages in'the way of adjustability. In the grindi1 g ofblades, it is necessary to adjust the height )f' the grinding wheel to'a nicety relative to the position of the blade. With the arrangement Ihave shown, if it is desired to lower the grinding wheel say oneone-hundredth of an' inch, the set screw, 24', upon the collar, 24. maybe loosened and the collar moved downward far enough to insert a feelergauge one one-hundredth of an inch in thickness between'the collar,- 24,and the sleeve, 22, The collar may then be pushed upward against thefeeler gauge and held in that 5 2 position while the set screw, 24, istightened.

.The set screw, 22, may then be'loosened, the

.feele'r, gauge withdrawn'and the sleeve, 22, allowed to slide down oneone-hundredth of an inch so as to rest upon the collar, 24 The setscrew, 22', 10

may then be tightened and the grinding wheel will have been lowered oneone-hundredth of an,

.inch.

Simflarly, if it is desired to raise the grinding wheel acne-hundredthof an inch, the set screw, 15 22', is loosened, the sleeve, 22, raisedslightly and a feeler gauge inserted between the sleeve, 22, and collar,24. The sleeve may then be lowered to rest upon the feeler gauge and theset screw, 22',

tightened. The set screw, 24', may then be 0 loosened,,the feeler gaugewithdrawn, and the collar, 24, moved upward in contact with the sleeve,22, and the set screw, 24', again tightened.

. In this way, the grinding wheel willhave beenraised one-hundredth ofan inch.

It is understood, of course, that the contacting surfaces of'the collar,24, and the sleeve, 22, must be ground and polished to 'a very highdegree to permit of such fine adjustments. It is obvious,

also, that the use of the collar,, 24, with the set 30 screw, 24',combined with the set screw, 22', forms a double locking means to securethe sleeve, 22,

at the desired height. A bracket, 2 I, is formed integral with thesleeve,

- 22." A motor, i8, has its; foot, J8, bolted to the 35 bracket, 2|,with bolts or cap screws 20 and 20', The bracket and foot of themotorare made .heavy enough to furnish a rigid support for the motor and themotor shaft, 26, is elongated and I made heavy enough to support oneormore grind- 4o 26, threaded upon the outer end of. the shaft, 26.

Upon the base, I, I form lugs. 2, which maybe cast integral with thebase. Upon the lugs, 3,

I mount pivotally, lugs, 6,which are .formedintegral with the table, 5.The-lugs,- 6, are secured to the lugs, 3, by a'pivotbolt, 8, whichpermits the table, 5, to tilt, and the nuts, 8'. upon the as The upperface of the support, 9, is beveled at desired angle to the top of thebase, I.

'Uponthe table, 5, I mount a blade support, 9. The top of the table, 5,and the bottom of the support, 9, are ground to smooth faces so that thesupport, 9, will slide readily upon the table, 5.

a suitable angle to assist in forming the proper angle or bevel at thecutting edges of the blades.

Pins, l and II, are rigidly secured in the,sup' port, hand spaced apartthe necessary distance to accommodate the desired cutting blade, ll,/to

be ground. In mounting the blade, I 3, upon thesupport, 9, the usualhole in one end of the blade,

I3, is placed over the pin, 10, and the hole in the opposite end of theblade, i3,- is engaged by a hook, l3, formed upon an extended end of atension spring, 12, the opposite end of which is hooked over the pin,Ii. The spring, I2, is made of sumcient strength and size to apply thenecessary strain to the cutting blade while being ground inorder to holdit rigidly upon the support, 9-.

A plurality of dowel pins, 0', are secured in the support,9, spaced onopposite sides of the grinding wheel and contact with the rear edge ofthe blade, i3, being ground so as to prevent displacement thereofrearwardly. The dowel pins, 9', are mounted in suitable openings in theupper face of the support, 0, and a pluralityof open nfl 9", may beprovided positioned as required for blades of different widths.

In order to properly gauge the support, 9, for

the successive serrations to be ground in the blades, ",1 provides.plurality of rectangular grooves, I, extending laterally in the bottomface thereof. Rectangular keys, I, are rigidly united grooves, 1'.

to the upper face of the table, I, extending parallel to the grindingwheels, II, and to the v grinding the blades at high speed, it isnecessary to provide some means for In order to permit cooling. same andI mount on my machine a waterpipe, I1, with a nozzle formed at the endthereof to project the water to the point of contact between thegrinding wheels and the blades. This waterpipe, l1, may belocated at apoint which will project vthe water to the point of contact between thegrinding wheel and the blade,

.tothebestadvantage. Imake no claimtoany particular position of thewa'terpipe, l1, and it is obvious that either water or any othersuitable coolingifluid may be employed.

In the operation of my machine, the support, Q, is 'slidback upon thetable, I, to the'position shown in dotted lines in Figure 2,'and theblade placed thereon asalready described.

The support is then slid along the top of the table, I, in position togrind the first serration' or scallop and the support is then pushedunder the grinding wheel, l5, until it'is ready to contact with thewheel. The table, -'i,-is then adjusted j to the desired angle and themotor started. The

support, will then be guided by the keys, I,

'- and then slidforward againupon the keys, 1,

ttii-grind the next succeeding scallop or serraon, llf.-. I The grindingwheels have a curved periphery,

any

ll, of thedesired'configuration. The grinding wheels may be made ofemery or carborundum or faced with diamond dust or other abrasive so asto stand long wear without requiring redressing, but may be redressed asnecessary in the usual wellknown manner.

with both front and rear edges straight or if desired, the cutting edgemay be stamped out into scallops of the desired configuration beforebeing ground.

The points between the scallops will form teeth, i4, and the scallopswill be uniformly beveled on both sides by the grinding process. Whenthe blade has been entirely ground upon one side, the support, 9, willbe slid back and the blade turned over and replaced, and then groundupon the opposite side in the same manner as above described. The numberof keys, I, may be varied to suit the requirements of each particularcase. In many instances, a single key centrally placed, will be suf- Theblanks forthe blades, l3, may be formed flcient, but in any event, thekeys should be so" formed and the number'of them so arranged as toinsure parallel travel of the support forwardly in its differentadjusted positions and to insure uniformity in the scallops orserrations, ll;

In order to speed up the operation of grinding,

a plurality of similar wheels may be mounted upon the shaft, 26, eitherdirectly or by mounting them upon a sleeve, it, which in turn may berigidly secured upon the shaft, 26.

when two adjacent scallops, M, are ground at grinding operations foreach side of the blade, but

they may be arranged to grind alternate scallops,

so that-only two grinding operations will be necessary for-each side andwhen driven at a more moderate speed, they may be arranged to cut all ofthe scallops on one side ofthe blade at a single grinding operation. Theeifect of cutting all the scallopsat once, will more than make up forthe 'loss of time in slowing down the speed of the grinding wheels. I IY The upper corner of the support, l, may be groundsuflicient toaccommodate the grindingwheel before the blades are placed thereon ifdesired or it may be ground at the same time that the blade placedthereon is ground.

It is obviousthat various equivalent means of gauging or positioning thesupport, 9, may be utilized and various modifications may be made in-myapparatus without departing from the spirit of my invention'and I do notlimit my claims to the precise forms shown in the drawings.-

It is obvious that this process permits blades to be ground while'heldina straight position and 'without any bending and will obviate the delaysincident to placing a bladeupona curved support and in grinding a singletime.

I claim: p I v 1. A blade grinding machine comprising a-fixed base, acolumn united-thereto,- a bracket adjustably mounted upon the column andslidable thereon, a collar adjustably mounted upon the column below andadjacent the bracket and slidable on 7; curved to cut a scallo or thecolumn, a motor with extended shaft mounted serration or scallop at aing ground in a succession of uniformly progres sive longitudinalpositions.

2. A blade grinding machine comprising a base,

a column united thereto, a bracket adjustably mounted upon the columncarrying a motor with extended shaft, a plurality of spaced grindingwheels keyed to theshaftreach having a convex periphery, means adaptedto support and carry a I blade into engagement with the periphery, atable tiltably mounted upon the base, a blade support slidable upon thetable, and means coacting between the table and the blade supportadapted to guide 'the support in predetermined successive, uniformlyspaced parallel lanes of travel to the grinding wheels.

3. A blade grinding machine comprising a base, a fixed vertical columnunited thereto, a bracket adjustably mounted upon the column with meanspermitting fine vertical adjustment thereof and adapted to rigidlysecure such bracket in its adjusted position upon the column, a motormounted upon said bracket with anextended horizontal shaft having agrinding wheel with convex periphery keyed to such shaft, and meanssupported above the base adapted to rigidly support and to carry aslicing blade into engagement with the peripheryo-f the grinding'wheelin a plurality of uniformly spaced successive positions longitudinallyof the blade and at a right angle td the plane of rotation of thegrinding wheel, and to hold such blades straight while being ground.

4. A blade grinding machine comprising a base,

a fixed vertical column united thereto, a bracket adjustably. mountedupon the column with'means permitting both coarse and fine adjustmentthereof and adapted to rigidly secure such bracket in its adjusted*position upon the column, a motor mounted upon said bracket with anextended horizontal shaft having a grinding wheel with convex peripherykeyed to such shaft,- and means supported above the base adapted tosupport and uniformly spaced successive horizontal positions and atright angles to the plane of rotation of the grinding wheel and to holdsuch blade straight while being ground. I Y.

5. A blade grinding machine comprisinga horizontal base, a fixedvertical column united there-' to, a bracket adjustably mounted upon thecolumn with means permitting fine adjustment thereof vertically andadapted to rigidly secure suc bracket in its adjusted position upon thecolumn, amotor mounted upon said bracket with an extended horizontalshaft having a grinding wheel with convex periphery keyed to such shaft,a tiltable table pivotally mounted upon the base under and spaced fromthe grinding wheel, an

extended wedge-shaped support manually slidable upon the table and meansunited to the support adapted to secure a blade "upon the upper facethereof and to hold said blade under tension in progressive contact withthe grinding wheel while being ground. v 6. A blade grinding machinecomprising a-horizontal base, a fixed vertical column united thereto, abracket adjustably mounted upon the column with means permitting fineadjustment thereof vertically and adapted to rigidly secure such bracketin its adjusted position upon the column,

a motor mounted uponsaid bracket with an extended horizontal shafthaving a grinding wheel with convex periphery keyed to such shaft, atiltable table pivotally mounted upon the base under and spaced from thegrinding wheel, an extended wedge-shaped support manually slidable bothlongitudinally and transversely upon the table, and means united to thesupport adapted to secure a blade upon the upper face thereof and tohold said blade under tension in progressive con-.

tact with the grinding wheel while being ground.

7. A blade grinding machine comprising a horizontalbase, a fixedvertical column united thereto,a bracket adjustably mounted upon thecolumn with means permitting fine adjustment thereof vertically andadapted to rigidly secure such bracket in its adjusted position upon thecolumn, a motor mounted upon said bracket with an extended horizontalshaft having a grinding wheel with convex periphery keyed to such shaft,a tiltable table pivotally mounted upon the base under and spaced fromthe grinding wheel, an extended wedge-shaped support manually slidableupon the table, and means united to the support adapted to secure ablade upon the upper face thereof and to hold said blade under tensionin progressive contact with the grinding wheel while being ground, andguiding means adapted to guide the support in a plurality ofuniformlyspaced progressive lines of travel parallel to the plane of thegrinding wheel.

8. A blade grinding machine comprising a horizontal base, a fixedvertical column united there to, a. bracket adjustably mounted upon thecolumn with means permitting fine adjustment thereof shaped supportmanually slidable both longitudinally and transversely upon the table,and means united to the supp rt adapted-to secure a blade upon the upperface thereof and to hold said blade under tensionin progressive contactwith the grinding wheel while being ground.

HARRY J. CRINER.

